JEE Mains · Physics · STD 12 - Ray optics and optical instruments
- JEE Mains 2026
- Easy
- MCQ
The magnitudes of power of a biconvex lens (refractive index 1.5) and that of a plano-concave lens (refractive index \(=1.7\)) are same. If the curvature of plano-concave lens exactly matches with the curvature of back surface of the biconvex lens, then ratio of radius of curvature of front and back surface of the biconvex lens is ___________ .
Pick an option to check your answer.
Answer & Solution
Correct Answer
(A) 5 : 2
Step-by-step Solution
Detailed explanation

\(\left| P _{ A }\right|=\left| P _{ B }\right|\)
\(0.5\left(\frac{1}{ R _1}+\frac{1}{ R _2}\right)=\frac{0.7}{ R _2}\)
\(\frac{5}{ R _1}=\frac{2}{ R _2}\)
\(\frac{ R _1}{ R _2}=\frac{5}{2}\)
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